The traffic sign assistance system currently offered in Mercedes-Benz’s S- and E-Class models uses a camera mounted on the inside of the front windscreen to identify speed restriction signs. This speed restriction information is relayed to the navigation system and displayed in the instrument cluster and in the map view to help prevent drivers exceeding the speed limit. Mercedes has now updated the system to also recognize no-overtaking zones and no-entry signs so as to prevent drivers from accidentally traveling in the wrong direction.

A couple of years ago while driving at night along a freeway, I noticed a pair of headlights traveling towards me. I assumed the vehicle they belonged to was traveling on the other side of the freeway and we were safely separated by a median strip. It wasn’t until the car actually sped past me no more than a couple of meters away that I realized the car was actually driving the wrong way. If I had been in the overtaking lane, I probably wouldn’t be sitting here today.

It is just such a scenario that Mercedes-Benz's new traffic sign assistance system is designed to prevent. According to German Federal Department of Transport estimates, around 1,700 radio warnings about wrong-way drivers – known in German as Geisterfahrer, which translates as “phantom drivers” – are issued annually. With many instances going unreported, actual occurrences of phantom drivers are certain to be much higher.

Mercedes' new system visually identifies no-entry signs and warns the driver with three loud beeps and the display of a red no-entry symbol in the instrument cluster if they are about to enter a road and head against the flow of traffic. The system now also recognizes no-overtaking signs. To improve its reliability, the system compares the traffic sign data captured by the camera with data from the navigation system.

With traffic signs differing from country to country, the new traffic sign assistance system is designed primarily for German roads. However, Mercedes says it is working on adapting the system for other countries. It will initially be available in Mercedes new S-Class and E-Class models before gradual introduction to other models.